It’s one of the nervous flier’s (numerous) nightmare scenarios. A fellow passenger makes a beeline for the emergency exit and yanks the door open, sending themselves, and any unsecured flight attendants and holidaymakers, spinning into the stratosphere.
Nightmare became reality last week, when a man in South Korea opened the door during an Asiana Airlines flight, causing panic on board as wind rushed through the cabin. Luckily, the plane was only a few hundred metres above the ground when the incident occurred, meaning the only injuries were minor (about a dozen passengers were taken to hospital after fainting or having breathing difficulties). Even still, the airline has said it will stop selling tickets for emergency exit seats on its A321-200 aircraft in response.
Had the door been opened at a higher altitude, causing the cabin to rapidly lose pressure, the result would have been far more dramatic.
Even instances of slow decompression, of which there are an estimated 40 to 50 a year, can be fatal. In 2005 a Boeing 737 operated by Helios Airways crashed, killing all 121 passengers and crew (the deadliest air disaster in Greek history), after a gradual loss of cabin pressure. The lack of oxygen at 30,000 feet left the crew incapacitated, and the plane – on auto-pilot – slowly ran out of fuel, before plunging to the ground.
In such instances, oxygen masks (with enough oxygen to last several minutes) should drop from the ceiling to stave off hypoxia (a lack of oxygen, which leads to sluggish thinking, dimmed vision, unconsciousness and then death). In the cockpit, the flight crew will don their rubber masks and begin a rapid descent to a safer altitude – anything below 10,000ft (mountainous obstacles notwithstanding).
Sudden decompression, which would occur if a plane door was suddenly thrust open, is another matter. Anyone standing near the exit would be ejected into the sky; the cabin temperature would quickly plummet to frostbite-inducing levels, and the plane itself might even begin to break apart.
In 1988, an Aloha Airlines flight (also a Boeing 737) with 90 people on board was en route to Honolulu, cruising at an altitude of 24,000 feet, when a small section of the roof ruptured. The resulting “explosive” decompression tore off a larger section of the roof, and a 57-year-old flight attendant called Clarabelle Lansing was swept from her seat and out of the hole in the aircraft. Luckily, all other passengers were belted up, and the pilot managed to land 13 minutes later, avoiding further loss of life.
Dozens of other examples of explosive decompression have been recorded, and it often doesn’t end well – such as in the case of Japan Airlines Flight 123, when such a decompression was caused by a faulty repair, leading the Boeing 747 to crash into the mountains in Gunma with the loss of 520 lives, making it the deadliest single-aircraft accident in history.
Fortunately, while decompression can be dangerous, it is not going to happen because a fellow flier fancied a bit of fresh air for one simple reason: it is simply impossible to open a plane door during a flight.
“Cabin pressure won’t allow it,” explains Patrick Smith, an airline pilot and author of Cockpit Confidential, a book about air travel. “Think of an aircraft door as a drain plug, fixed in place by the interior pressure. Almost all aircraft exits open inward. Some retract upward into the ceiling; others swing outward; but they open inward first.
“At a typical cruising altitude, up to eight pounds of pressure are pushing against every square inch of interior fuselage. That’s over 1,100 pounds against each square foot of door.
“A meager two pounds per square inch is still more than anyone can displace – even after six cups of coffee and the aggravation that comes with sitting behind a shrieking baby. The doors are further secured by a series of electrical and/or mechanical latches. You would need a hydraulic jack, and airport security doesn’t allow those.”
But there has been at least one incident when a passenger did manage to open the door of an aircraft while it was in the sky. In 1971 “Dan ‘D B’ Cooper” hijacked a Boeing 727, extorted a $200,000 ransom (over $1m in today’s money), and then leapt from the rear exit with a parachute, never to be seen again. However, he had the pilot depressurise the plane in order to do so, while a year later “Cooper vanes” were installed to completely disable aircraft doors while the landing gear is up. (Incidentally, the reason skydivers or military personnel can regularly leap from aircraft doors is because those planes are not pressurised.)
All of which explains why the recent Asiana Airlines incident was possible: the plane involved was coming into land, only a few hundred metres above the ground, so the landing gear was down and the door had been unlocked (as one would hope, with the possibility of an evacuation in mind), while the pressure forcing it closed was non-existent. It has also been suggested that the A321’s doors, which slide open parallel to the rest of the plane, are easier to open against the force of the wind.
Smith adds: “While the plane is taxiing, you will get the door to open. You will also activate the door’s emergency escape slide. As an aircraft approaches the gate, you will sometimes hear the cabin crew calling out ‘doors to manual’. This has to do with overriding the automatic deployment function of the slides. Those slides can unfurl with enough force to kill a person, and you don’t want them billowing onto the jet bridge or into a catering truck.”